In order to electrically connect electric equipments, a cable structure is used. The cable structure contains a cable and a connector connected to an end of the cable. In the cable structure, there is a case where a water drop is generated on the cable by condensation. When the water drop runs down the cable to enter into the connector, electric connection may be disturbed. So, a water-proof means is provided in the cable structure.
As an example of the water-proof means, a drip loop can be listed. FIGS. 1A and 1B show examples of the cable structure in which the drip loop is provided, respectively. A cable structure 100 shown in FIG. 1A has a cable 101 and a connector 102 attached to one end of the cable 101. The cable 101 is bent at the vicinity of the connector 102, and a drip loop 103 is formed thereby. Similarly, the cable structure 100 shown in FIG. 1B has the cable 101 and the connector 102. The connector 102 is arranged to be downward. The cable 101 is bent at the vicinity of the connector to be convex upward, and the drip loop 103 is formed thereby. Since the drip loop 103 is formed, the water drop on the cable 101 is prevented from reaching the connector 102.
As another example of the water-proof means, potting can be listed. FIG. 2 is a schematic view showing the other example of the cable structure. In the cable structure shown in FIG. 2, a potting portion 104 is provided to cover a connection portion between the cable 101 and the connector 102. The potting portion 104 prevents liquid droplets on the cable 101 from entering into the connector 102.
Also, a different related technique is described in a patent literature 1 (Japanese Unexamined Utility Model (Registration) Application Publication No. H06-44045 U). The patent literature 1 discloses a water-proof code connector that is provided with: a connector body having a plurality of blade and an outer cap fitting with the connector body. This water-proof code connector has an insertion cylinder having an opening through which an electric wire code is inserted, in the outer shell cap. On the inner wall of the insertion cylinder, a plurality of water-proof valve are circumferentially arranged at many stages for protecting the water entering into the outer shell cap. One water-proof valve is arranged on the opening side via a winding groove placed on the inner wall of the insertion cylinder. Also, the plurality of water-proof valves are arranged on the inward side of the outer shell cap via the winding groove on the inner wall of the insertion cylinder.